The present invention relates to a vehicle drivetrain control including a continuously variable transmission (CVT).
U.S. Pat. No. 4,735,113, issued to Yamamuro et al. on Apr. 5, 1988 discloses a continuously variable transmission incoporated in a transaxle drivingly connected traction road wheels of a vehicle. According to this drivetrain, for forward drive, a forward clutch is kept engaged to transfer the engine power to the CVT input shaft rotatable with a driver pulley. Under condition where the traction road wheels are locked to hold the CVT output shaft stationary, the CVT is subject to a stress if engine power is kept applied to the CVT input shaft. This stress, if great, induces occurrence of a slip of the V-belt relative to the pulleys.
An object of the present invention is to improve a vehicle drivetrain including a continuously variable transmission such that the amount of stress which the transmission is subject to is decreased to a sufficiently low level without degrading drive feel of the vehicle.